• MeSH
• řízení kvality MeSH
• sterilizace * metody   normy   přístrojové vybavení   MeSH

Hydrogen peroxide (H2O2) operates as a signaling molecule in eukaryotes, but the specificity of its signaling capacities remains largely unrevealed. Here, we analyzed whether a moderate production of H2O2 from two different plant cellular compartments has divergent effects on the plant transcriptome. Arabidopsis thaliana overexpressing glycolate oxidase in the chloroplast (Fahnenstich et al., 2008; Balazadeh et al., 2012) and plants deficient in peroxisomal catalase (Queval et al., 2007; Inzé et al., 2012) were grown under non-photorespiratory conditions and then transferred to photorespiratory conditions to foster the production of H2O2 in both organelles. We show that H2O2 originating in a specific organelle induces two types of responses: one that integrates signals independently from the subcellular site of H2O2 production and another that is dependent on the H2O2 production site. H2O2 produced in peroxisomes induces transcripts involved in protein repair responses, while H2O2 produced in chloroplasts induces early signaling responses, including transcription factors and biosynthetic genes involved in production of secondary signaling messengers. There is a significant bias towards the induction of genes involved in responses to wounding and pathogen attack by chloroplastic-produced H2O2, including indolic glucosinolates-, camalexin-, and stigmasterol-biosynthetic genes. These transcriptional responses were accompanied by the accumulation of 4-methoxy-indol-3-ylmethyl glucosinolate and stigmasterol.

• MeSH
• Arabidopsis cytologie   účinky léků   genetika   metabolismus   MeSH
• chloroplasty účinky léků   metabolismus   MeSH
• geneticky modifikované rostliny MeSH
• genom rostlinný genetika   MeSH
• kinetika MeSH
• metabolomika MeSH
• oxid uhličitý farmakologie   MeSH
• peroxid vodíku metabolismus   MeSH
• peroxizomy účinky léků   metabolismus   MeSH
• stigmasterol metabolismus   MeSH
• transkriptom * účinky léků   MeSH
• tryptofan metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• MeSH
• aromatické uhlovodíky chemie   škodlivé účinky   MeSH
• chemické znečištění vody MeSH
• čištění vody MeSH
• dekontaminace metody   MeSH
• financování organizované MeSH
• fotolýza MeSH
• methylethery chemie   škodlivé účinky   MeSH
• peroxid vodíku MeSH

NADPH facilitates glucose-stimulated insulin secretion (GSIS) in pancreatic islets (PIs) of β-cells through an as yet unknown mechanism. We found NADPH oxidase isoform 4 (NOX4) to be the main producer of cytosolic H2O2, which is essential for GSIS; an increase in ATP alone was insufficient for GSIS. The fast GSIS phase was absent from PIs from NOX4-null, β-cell-specific knockout mice (NOX4βKO) (though not from NOX2 knockout mice) and from NOX4-silenced or catalase-overexpressing INS-1E cells. Lentiviral NOX4 overexpression or H2O2 rescued GSIS in PIs from NOX4βKO mice. NOX4 silencing suppressed Ca2+ oscillations, and the patch-clamped KATP channel opened more frequently when glucose was high. Mitochondrial H2O2, decreasing upon GSIS, provided alternative redox signaling when 2-oxo-isocaproate or fatty acid oxidation formed superoxides through electron-transfer flavoprotein:Q-oxidoreductase. Unlike GSIS, such insulin secretion was blocked with mitochondrial antioxidant SkQ1. Both NOX4 knockout and NOX4βKO mice exhibited impaired glucose tolerance and peripheral insulin resistance. Thus, the redox signaling previously suggested to cause β-cells to self-check hypothetically induces insulin resistance when it is absent. In conclusion, increases in ATP and H2O2 constitute an essential signal that switches on insulin exocytosis for glucose and branched-chain oxoacids as secretagogues (it does so partially for fatty acids). Redox signaling could be impaired by cytosolic antioxidants; hence, those targeting mitochondria should be preferred for clinical applications to treat (pre)diabetes at any stage.

• MeSH
• draslíkové kanály fyziologie   MeSH
• glukosa farmakologie   MeSH
• inzulinová rezistence MeSH
• kultivované buňky MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• NADPH-oxidasa 4 fyziologie   MeSH
• peroxid vodíku metabolismus   MeSH
• sekrece inzulinu * MeSH
• signální transdukce fyziologie   MeSH
• vápník metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The Non-invasive Micro-test Technique (NMT) is used to measure dynamic changes of specific ions/molecules non-invasively, but information about hydrogen peroxide (H2O2) fluxes in different classes of roots by mycorrhiza is scarce in terms of NMT. Effects of Funneliformis mosseae on plant growth, H2O2, superoxide radical (O2·-), malondialdehyde (MDA) concentrations, and H2O2 fluxes in the taproot (TR) and lateral roots (LRs) of trifoliate orange seedlings under well-watered (WW) and drought stress (DS) conditions were studied. DS strongly inhibited mycorrhizal colonization in the TR and LRs, whereas mycorrhizal inoculation significantly promoted plant growth and biomass production. H2O2, O2·-, and MDA concentrations in leaves and roots were dramatically lower in mycorrhizal seedlings than in non-mycorrhizal seedlings under DS. Compared with non-mycorrhizal seedlings, mycorrhizal seedlings had relatively higher net root H2O2 effluxes in the TR and LRs especially under WW, as well as significantly higher total root H2O2 effluxes in the TR and LRs under WW and DS. Total root H2O2 effluxes were significantly positively correlated with root colonization but negatively with root H2O2 and MDA concentrations. It suggested that mycorrhizas induces more H2O2 effluxes of the TR and LRs, thus, alleviating oxidative damage of DS in the host plant.

• MeSH
• biomasa MeSH
• fyziologický stres * MeSH
• lineární modely MeSH
• malondialdehyd metabolismus   MeSH
• mykorhiza růst a vývoj   fyziologie   MeSH
• období sucha * MeSH
• peroxid vodíku metabolismus   MeSH
• počet mikrobiálních kolonií MeSH
• Poncirus mikrobiologie   fyziologie   MeSH
• superoxidy metabolismus   MeSH
• voda metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Cells produce reactive oxygen species (ROS) as a metabolic by-product. ROS molecules trigger oxidative stress as a feedback response that significantly initiates biological processes such as autophagy, apoptosis, and necrosis. Furthermore, extensive research has revealed that hydrogen peroxide (H2O2) is an important ROS entity and plays a crucial role in several physiological processes, including cell differentiation, cell signalling, and apoptosis. However, excessive production of H2O2 has been shown to disrupt biomolecules and cell organelles, leading to an inflammatory response and contributing to the development of health complications such as collagen deposition, aging, liver fibrosis, sepsis, ulcerative colitis, etc. Extracts of different plant species, phytochemicals, and Lactobacillus sp (probiotic) have been reported for their anti-oxidant potential. In this view, the researchers have gained significant interest in exploring the potential plants spp., their phytochemicals, and the potential of Lactobacillus sp. strains that exhibit anti-oxidant properties and health benefits. Thus, the current review focuses on comprehending the information related to the formation of H2O2, the factors influencing it, and their pathophysiology imposed on human health. Moreover, this review also discussed the anti-oxidant potential and role of different extract of plants, Lactobacillus sp. and their fermented products in curbing H2O2‐induced oxidative stress in both in-vitro and in-vivo models via boosting the anti-oxidative activity, inhibiting of important enzyme release and downregulation of cytochrome c, cleaved caspases-3, - 8, and - 9 expression. In particular, this knowledge will assist R&D sections in biopharmaceutical and food industries in developing herbal medicine and probiotics-based or derived food products that can effectively alleviate oxidative stress issues induced by H2O2 generation.

• MeSH
• antioxidancia * farmakologie   metabolismus   MeSH
• apoptóza MeSH
• lidé MeSH
• oxidační stres MeSH
• peroxid vodíku farmakologie   MeSH
• probiotika * farmakologie   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• rostliny metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

This study was performed to test the feasibility of several decontamination methods for remediating heavily contaminated groundwater in a real contaminated locality in the Czech Republic, where a pharmaceuticals plant has been in operation for more than 80 years. The site is polluted mainly by recalcitrant psychopharmaceuticals and monoaromatic hydrocarbons, such as benzene, toluene and chlorobenzene. For this purpose, an advanced oxidation technique employing UV radiation with hydrogen peroxide dosing was employed, in combination with simple aeration pretreatment. The results showed that UV/H2O2 was an efficient and necessary step for degradation of the pharmaceuticals; however, the monoaromatics were already removed during the aeration step. Characterization of the removal mechanisms participating in the aeration revealed that volatilization, co-precipitation and biodegradation contributed to the process. These findings were supported by bacterial metabolite analyses, phospholipid fatty acid analysis, qPCR of representatives of the degradative genes and detailed characterization of the formed precipitate using Mössbauer spectroscopy and scanning electron microscopy. Further tests were carried out in a continuous arrangement directly connected to the wells already present in the locality. The results documented the feasibility of combination of the photo-reactor employing UV/H2O2 together with aeration pretreatment for 4 months, where the overall decontamination efficiency ranged from 72% to 99% of the pharmaceuticals. We recorded even better results for the monoaromatics decontamination except for one month, when we encountered some technical problems with the aeration pump. This demonstrated the necessity of using the aeration step.

• MeSH
• benzen MeSH
• biodegradace MeSH
• chemické látky znečišťující vodu * MeSH
• chlorbenzeny MeSH
• léčivé přípravky MeSH
• peroxid vodíku MeSH
• podzemní voda * MeSH
• toluen MeSH
• znečištění životního prostředí prevence a kontrola   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH

Methylene blue (MB) is a promising compound with a broad range of neuroprotective activity. One of therapeutic effects is the activation of mitochondrial biogenesis via Nrf2/ARE signaling cascade. Probably, mild oxidative stress caused by MB-depended H2O2 production is a trigger for activation of this signaling cascade. So mechanistically, MB can be regarded as prooxidant. We investigated the dose-dependent H2O2 production in intact brain mitochondria and showed the increase in the H2O2 production after adding as little as 50 nM MB. We have not found genotoxic effect of therapeutic concentration of MB to mitochondrial genome. 100 μM MB selectively damaged fragments of mitochondrial DNA, which correlated with the number of purine-T-G-purine (RTGR)-sequences in studied fragments. Furthermore, 20 μM MB combined with the red light caused the formation of singlet oxygen, which strongly damaged mitochondrial DNA in all studied fragments. We did not observe mitochondrial DNA lesions in brain after single intraperitoneal injection of MB in the concentration of 50 mg/kg. Furthermore, we showed the neuroprotective properties of MB pretreatments after rotenone injection. Therefore, we suggest that MB-induced mild oxidative stress does not have genotoxic effect on mitochondrial DNA.

• MeSH
• insekticidy škodlivé účinky   MeSH
• laboratorní zvířata MeSH
• methylenová modř farmakologie   terapeutické užití   MeSH
• mitochondriální DNA účinky léků   MeSH
• mitochondrie účinky léků   MeSH
• modely nemocí na zvířatech MeSH
• mozek metabolismus   účinky léků   ultrastruktura   MeSH
• myši MeSH
• neuroprotektivní látky MeSH
• peroxid vodíku farmakologie   metabolismus   MeSH
• poškození DNA genetika   účinky léků   MeSH
• rotenon * škodlivé účinky   MeSH
• techniky in vitro MeSH
• Check Tag
• myši MeSH
• Publikační typ
• práce podpořená grantem MeSH

The production of hydrogen peroxide (H(2)O(2)) was investigated by means of cytochemical reaction with cerium chloride in human embryos cryostoraged for a long time period. The sites of H(2)O(2) generation were demonstrated at submicroscopic level in both freshly thawed embryos and in embryos and blastocysts formed after subsequent culture. The intact blastomeres as well as cells of well developed blastocysts did not produce any H(2)O(2). Two main intracellular sites of H(2)O(2) production were identified: mitochondria and plasma membranes. Some alterations and often destruction of plasma membrane integrity accompanied by massive H(2)O(2) generation are believed to be caused by the freezing and thawing.

• MeSH
• blastomery metabolismus   MeSH
• kryoprezervace MeSH
• kultivace embrya MeSH
• lidé MeSH
• peroxid vodíku metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Abiotic stress poses constant challenges for plant survival and is a serious problem for global agricultural productivity. On a molecular level, stress conditions result in elevation of reactive oxygen species (ROS) production causing oxidative stress associated with oxidation of proteins and nucleic acids as well as impairment of membrane functions. Adaptation of root growth to ROS accumulation is facilitated through modification of auxin and cytokinin hormone homeostasis. Here, we report that in Arabidopsis root meristem, ROS-induced changes of auxin levels correspond to decreased abundance of PIN auxin efflux carriers at the plasma membrane (PM). Specifically, increase in H2O2 levels affects PIN2 endocytic recycling. We show that the PIN2 intracellular trafficking during adaptation to oxidative stress requires the function of the ADP-ribosylation factor (ARF)-guanine-nucleotide exchange factor (GEF) BEN1, an actin-associated regulator of the trafficking from the PM to early endosomes and, presumably, indirectly, trafficking to the vacuoles. We propose that H2O2 levels affect the actin dynamics thus modulating ARF-GEF-dependent trafficking of PIN2. This mechanism provides a way how root growth acclimates to stress and adapts to a changing environment.

• MeSH
• ADP-ribosylační faktory metabolismus   fyziologie   MeSH
• aktiny metabolismus   MeSH
• alkoholoxidoreduktasy metabolismus   fyziologie   MeSH
• Arabidopsis metabolismus   fyziologie   MeSH
• cytoskelet metabolismus   MeSH
• fyziologická adaptace MeSH
• kořeny rostlin metabolismus   fyziologie   MeSH
• oxidační stres * MeSH
• peroxid vodíku metabolismus   MeSH
• proteiny huseníčku metabolismus   fyziologie   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• výměnné faktory guaninnukleotidů metabolismus   fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH